Rotating-piston compressor



Aug. 22, 1967 BULUTAY 3,337,123

ROTATING-PISTON COMPRESSOR Filed Nov. 28, 1966 7 4 SheetsShee't 1 FIG. I

INVENTOR ATTILA" BULUTAY AGENT v Aug. 22, 1967 A. BULUTAY 3,337,123

' ROTATING-PISTON COMPRESSOR Filed Nov. 28, 1966 4 Sheets-Sh0etINVENTORY ATTILA BU'LUTAY zwi AGENT Aug. 22, 1967 A. BULUTAYROTATING-PISTON COMPRESSOR Filed Nov. 28, 1966 4 Sheets-Sheet PEG. 5

mVE NTOR ATTILA BULUTAYY v Q BY AGENT United States Patent 3,337,123ROTATING-PISTON COMPRESSOR Attila Bulutay, Kizilirmak Sokak 7/2, Akay,Ankara, Turkey Filed Nov. 28, 1966, Ser. No. 597,414 Claims priority,applicairgitzrig'lurkey, Nov. 26, 1965,

10 Claims. (or. 230-144 ABSTRACT OF THE DISCLOSURE Various types ofcompressors are known which use different principles for theiroperation. It has been determined some time ago that any oscillatory orirregular motion, such as that of reciprocating pistons, producesvibrations and subjects the compressor to undue wear. Thus, preferencehas been given to rotary-action compressors, among which are screwtypes, centripetal, centris fug-al, and other systems.

The present invention has as one of its major objects to dispense withthe drawbacks and inherent disadvantages of hitherto used compressortypes. A rotary-motion, forced-action compressor is provided whichcombines smooth operation with economical output and reliableperformance.

It is another important object of the invention to provide such acompressor which allows a wide range of adjustability, for controllingthe suction and compression phases, the output capacity, and/ or theejection pressure of the inventive compressor, even independently fromeach other.

It is yet another object of the invention to dispense entirely withvalves which are usually the source of disturbances in hitherto usedtypes of compressors.

According to one of the important structural features of the inventiverotating-piston compressor, there are provided two coaxial shafts,preferably one hollow and surrounding the other, which are driven byrespective universal-joint systems. The latter provide periodicadvancing and lagging movements in the shafts, and the piston membersassociated therewith, while they rotate in the same direction but withdifferent and changin peripheral velocities.

According to the invention, consecutive piston members within a commoncylinder space define compression spaces or volumes which areperiodically expanded and contracted during the rotation of the shaftswith the piston members. Preferably, a phase difference of 90 isprovided between the movements of the two shafts.

Another feature of the invention relates to the provision of a linerinside the cylinder body, preferably press-fitted thereinto, the linerhaving cut-outs which correspond in their lengths to the arcuate outersides of the piston members. In a preferred, exemplary embodiment, thisarrangement results in substantially identical operational phases for(A) suction, (B) suction with compression, and (C) compression, followedby a much shorter phase (D) of compression with suction. These phasesrepeat themselves twice during each revolution of the driving shaft.

In the inventive compressor, the shaft velocities are reduced twice andincreased twice during one complete revolution of the two coaxialshafts. The resulting suction and compression allows the sucked-in airor other galses to be ejected or delivered to a tank or the atmosp ere.

Another feature of the invention relates to that the drivinguniversal-joint systems are applied in a manner to present a phasedifference. Thus the suction and compression ratios are increased to amaximum. The maximum slow-down in the velocity of the one shaft, and themaximum speeding-up of the velocity of the other, are synchronized andthis is performed in a periodical manner, as has been mentioned before.

A further feautre relates to the adjustability of the suction andcompression ratios, by simply changing the specific angle between theaxis of the coaxial shafts, on the one hand, and the axis of the drivingshaft, on the other hand.

Yet another feature relates to that different compression ratios may beobtained by the facility of making the rotating pistons with larger orsmaller volumes therebetween, which thus vary the overall volume of thepistons, occupying the total cylinder space.

The suction and compression ratios of the inventive compressor can bebrought to :any desired rating by changing the phase .difierence of theuniversal-joint sys-v tems of the two shafts to any desired degree.

Another feature of the invention relates to that the pairs of suctionand compression sections in the cylinder space are kept unchanged duringoperation, without any relocation thereof. The channels leading to theafore-v mentioned sections make for uninterruped and continuous suctionand compression, without the necessity for valves and/or flaps.

Yet a further feature of the compressor relates to the facility ofoperating the same even in reverse direction,

In this mode of'opera-tion, the suction sections and phases of coursebecome compression sections and phases, and vice versa. Gas or air isthen withdrawn through the outlet channels, and it is delivered throughthe intake channels.

Yet another feature of the inventive compressor relates to theexpedientaccording to which the lubrication of the cylinder may beprovided by dripping lubricants into the sucked-in air or gas, orspraying the lubricants into the cylinder through pin holes which can beopened to;

the suction sections of the cylinder.

The various objects, features and attendant advantages of the presentinvention will become more apparent from the following description of apreferred exemplary em-- bodiment of the rotating-piston compressoraccording to the-invention, when considered in conjunction withtheaccompanying drawings, wherein FIG. 1 is a top view of therotating-piston compressor according to the invention;

FIGS. 2a and 2b are partial vertical axial cross-sectional andside-elevational views of-the compressor shown in FIG. 1, taken alongline 2a, 2b of FIG. 3, wherein FIG. 2a illustrates two universal-jointsystems for providing a periodical phase difference between thevelocities of the I two compressor shafts, while FIG. 2b illustrates thecompressor proper;

FIG. 3 is a vertical cross-sectional view taken along line 3-3 of FIG.2b;

'FIG. 4a is a sectional detail -view of the rotating pistons, takenalong line 4a4a of FIG. 3;

FIG. 4b is another sectional detail view of the pistons, at right anglesto FIG. 4a, taken along line 4b4b of FIG. 2b;

FIG. 5 is a schematic illustration of the specific angle between thedriving and the driven shafts of the compressor; and

FIG. 6 is a schematic showing of the operational phases in the rotatingpistons, similar to the showing of FIG. 3, for explanatory purposes.

The inventive rotating-piston compressor will now be described withreference to the top view of FIG. 1 and the partial views of FIGS. 2aand 2b, the two together showing the compressor on a somewhat enlargedscale so as to illustrate all important details. FIG. 3 and the detailviews of FIGS. 4a, 4b give cross-sectional details of the rotatingpistons and the operative spaces therebetween.

A bracket pad or plate 31 (omitted from FIG. 2:1 for the sake ofclarity) serves as a chassis for the compressor which is secured theretoby way of nuts 47 and bolts 49, with spring washers 46, 48 beingpreferably interposed therebetween.

I The compressor is driven by an input shaft 1 forming part or beingoperatively connected with a suitable prime mover. Within thecompressor, there are two driven shafts, namely an inner shaft 16 and ahollow shaft 17 surrounding the former. Before the actual compressorcomponents canbe dealt with, the two universal-joint systems will bedescribed, as shown in FIGS. 1 and 2a, which are interposed between thedriving or input shaft 1, on the one hand, and the driven shafts 16, 17,on the other, so as to provide a periodical phase difierence between thevelocities of these shafts, as will be fully explained hereunder.

Shaft 1 has connected thereto separate but coaxial and synchronouslyrotating yokes 32, 33, substantially perpendicular with respect to eachother, to obtain 90 phase difference between said yokes, one for eachuniversaljoint system. Following up first the yoke 32, which cooperatesin driving the hollow shaft 17 with a periodically changing velocity, itis linked to conjugated ring members 4a, 4b by the intermediary ofneedle bearings 6 and lock rings 5 (see FIG. 2a). The members 4a, 4b areinter-connected by means of bolts and nuts 2.

In the position shown in FIGS. 1 and 2a, yoke 32 is substantially in thehorizontal plane and ring members 4a, 4b are in a plane perpendicular tothe yoke 32 and to the axis of shaft 1. At respective angles of A (shownin FIG. 5) and 180 minus A, a second yoke 38 is journ'aled to the ringmembers 4a, 4b, similarly by the intermediary of bearings 6 and lockrings 5. The illustrated, preferred embodiment. is made for A=40. Theyoke 38 is perpendicular to the hollow shaft 17. As shown in thedrawings, the two pairs of bearings cooperating with the ring membersare disposed diametrally, and at right angles with respect to the otherpair, for the driving and the driven yokes 32, 38, respectively.

, An oil seal 3 is shown between the bearings 6 and the limbs of yoke38, and similar seals may of course be provided for the other junctionsof this and of the other universal-joint system. By way of a key 9, theyoke 38 is axially connected for driving the hollow shaft 17.

As to the other yoke 33, which cooperates in driving the shaft 16 insidethe shaft 17 and independently therefrom, it is linked to conjugatedring members 35a, 35b similar to but smaller than the afore-mentionedmembers 4a, 4b. It will be seen from the drawings that yoke 32 and rings4a, 4b are larger than their counterparts 33, 35a, 35b, respectively, sothat the system of shaft 16 can freely rotate within that of shaft 17Here, again, there may be needle bearings and lock rings, as in thepreviously described universal-joint system. Bolts and nuts 34 serve forinterconnecting the members 35a, 35b and they are of course thecounterparts of bolts and nuts 2.

In the position shown in FIGS. 1 and 2a, yoke 33 is substantially in thevertical plane and ring members 35a, 35b are in -a plane at respectiveangles of 40 and 140 with respect to the yoke 33 and to the axis ofshaft 1. In a plane perpendicular to the axis of shaft 16 and to thering members 35a, 35b, a second yoke 37 is journaled to the latter,preferably also by the inter-mediary of bearings and lock rings. Thebearing pairs are again disposed diametr-ally, at right angles for thedriving and driven yokes 33, 37, respectively.

Oil seals 3 are again shown for this system. The yoke 37 is axially,directly (by way of a conventional key) or otherwise, connected to theend of shaft 16 for driving the same, independently from hollow shaft17. An oil seal 8 may be interposed between the enlarged end of shaft 16and the outer end of hollow shaft 17 so as to prevent lubricants toescape from between the two shafts, in a conventional manner.

The compressor proper includes a body 18. At the end where the shafts16, 17 enter, there is a cap 11 having an oil seal 10 therein whichsurrounds the outer shaft 17.

Between the cap 11 and the body 18 there is a bearing cap 12 inside ofwhich there are conventional needle bearings 13, with bushes 14therebetween, for journaling the hollow shaft 17 and the shaft 16therein. At one or more locations along the shaft 17, bearing needles 15are disposed within annular or other appropriately shaped recessesaround shaft 16, for journaling the same within shaft 17, so as toassist their rotation independent from each other. Packings 19 surroundthe shaft 17.

The previously mentioned FIGS. 2b, 3, 4a and 4b are referred to for mostof the components to be described hereafter. Cylinder caps 20 straddle acylinder body 21 which may be provided with heat-exchange fins, as shownin FIG. 3. Rotating piston members 23 and 58 are keyed to shafts 17 and16, respectively, as shown in FIG. 3,

and members 23 have threaded bores therein for countersunk bolts 22 (seeFIG. 2b). A cylinder liner 26 surrounds the piston members 23 and 58.The afore-Inentioned packings 19 are secured to cylinder caps 20 by wayof packing bushes 28 and associated bolts 29. Liner 26 is press-fittedin body 21.

At the end of the compressor opposite the entrance of shafts 16, 17,cylinder cap 20 is flanked by another cap member 27 and at this end, acap 30 is removably attached so as to allow access to the end of shaft16. At the opposite compressor end, the cap 11 and the bearing cap 12are held to the body 18 by means of bolts 39, gaskets 40 and 41 beingrespectively interposed between the aforementioned elements, as shown inFIGS. 1 and 2b. Plugs 36 and 42 are provided at strategic points of thecompressor casing for allowing lubricants to be introduced and drained,respectively. Between portions of the casing 18, the caps 20 and thecylinder body 21, gaskets 44 and 45 are interposed; there is a similargasket 50 between the cap member 27 and the end cap 30 of thecompressor, as shown.

Numerals 51 identify attaching bolts similar to those shown at- 39, andmentioned before; appropriate nut-s 53 and optional spring washers 52are also shown (e.g. in FIG. 1) between the structural elements of thecompressor. Similarly, bolts 54 and spring washers 55 are provided forholding the elements together, in conjunction with nuts 56 (see FIGS. 1and 2b).

Again referring to FIGS. 3, 4a and 4b, the piston members 58 associatedwith the shaft 16 are disposed at angularly offset locations withrespect to the piston members 23 of shaft 17. Between the respectivepiston members 23, 58 and the shafts 17, 16, there are piston rings 62(see FIG. 3) While on the outer sides of the members 58, facing thecylinder liner 26, there are additional piston rings 63. The latter arealso shown in FIGS. 4a and 4b; in the former, springs 64 are also shownwhich are lodged in appropriate bores of the piston members 23 and 58.Each set of pistons and shafts can be made as a single unit. Referringnow to FIGS. 1, 2b and 3 only, there are shown diametrally disposedinlet pipes 43 and 57, the latter being provided with a lubricatingvalve 24. In another plane, axially spaced apart from the plane of theinlet pipes, there are two diametrally disposed and preferablyinterconnected outlet or delivery pipes 25. The aforementioned pipes 43,57 and 25 are preferably provided with sockets 60, coupling adapters 61,and gasket rings 59 interposed between the adapters 61 and theappropriately shaped connecting portions of the cylinder body 21.

In FIG. 3, operative compressing spaces 65, 66, 67 and 68 are formedbetween successive pairs of piston members 58 and 23 (then 23 and 58,and so forth). These spaces or volumes are aligned with respectivechannels 69, 70, 71 and 72, respectively connected with theaforementioned pipes 57, 25, 43 and 25, in this order. The operation ofthe compressor will be described as the description proceeds.

FIG. 5 is a schematic, explanatory illustration of the angularrelationship between the shaft 1 and the shafts 16, 17; this view alsoshows the aforementioned specific angle A defined between the respectiveaxes of these shafts, as will be explained somewhat later.

Coming now to the operation of the inventive rotatingpiston compressor,it will be understood from the structural description that, during theirrotation, the shafts 16, 17 perform advancing and lagging movementsrelative to one another, as a result of which the volumes 65 to 68between the pairs of rotating pistons 58, 23 periodically expand andcontract. This provides the suction and discharge (intake and delivery)effects of the compressor. The diametrally opposite channels 69, 71maintain constant suction while the other pair of channels 70, 72discharges the compressed air or gases. The expansion and contraction ofthe volumes 65 to 68 takes place twice during each revolution of thedriving shaft 1.

When volumes 65, 67 contract, that is in the compress ing position,volumes 66, 68 simultaneously expand, that is, they are at intakeposition. Subsequently, volumes 66, 68 become ready for compressing, andvolumes 65, 67 for intake. This repeats itself periodically. Thecompression performed by the device is thus a rotary-motion, forcedcompression.

Channels 69, 71 in cylinder 21 maintain constant suction, that is air orgas is made to enter the cylinder. Simultaneously, channels 70, 72maintain constant discharge of compressed air or gas from the cylinder.It should be noted that the lengths of the channels 69 to 72substantially correspond, in peripheral direction, to the lengths ofarcuate outer sides of the piston members 23, 58, owing to appropriatecut-outs provided in the cylinder liner 26, as shown in FIG. 3. Thus,the piston members 23, 58 completely block the entrances to the channelswhen they coincide with the liner cut-outs during their rotation.

Reference should be had at this point to the schematic, illustrativeshowing of the operational phases in the cylinder volumes, as shown inFIG. 6. For the sake of better understanding, the channels 69 to 72 andthe respective cut-outs in cylinder liner 26 have been shown in a singleplane rather than ofliset by pairs, as in actual construction (see FIG.3). Since both expansion and contraction or compression take place twiceduring one revolution of the shafts 16, 17, there will be four distinctphases of operation during each half revolution, as identified in FIG. 6by letters, to wit:

A-suction phase;

Bsuction phase, compressing section;

Ccompression phase; and

Dcompression phase, suction section.

The compression ratio can be adjusted by accordingly dimensioning thepiston members 23, 58, as well as the angle A between the shaft 1 andthe shafts 16, 17.

The output capacity of the compressor can be controlled by changing therotational speed of the driving shaft 1 and/ or the volume of thecylinder 21.

The ejection pressure of the compressor may be increased byadministering compressed air to the intake pipes 43 and/or 57.

Lubrication of the cyilnder 21 and of the shafts 16, 17 in the cylinder21 is made possible, for example, by dripping lubricants into the air orgas entering the intake pipes 43, 57; the lubricating valve 24 shown forpipe 57 is an exemplary solution. Also, lubricant may be sprayed in byway of small holes provided in the cylinder caps 20 or the cylinderwall; another possible solution resides in spraying a lubricant in asimilar manner into the intake sections of the cylinder caps, the pinholes (not shown) having direct connection with the layer of oil in thecylinder body. The lubricant which becomes intermixed with thecompressed air or gas can be removed in a conventional way by oilretainers (not illustrated) to be disposed at the discharge end of thecompressor.

It will be understood that the components of the compressor, and mainlythe cylinder 21, the caps 20 and the shafts 16, 17, may be made offriction and corrosion resistant materials.

It should be noted that there is no need to provide either valves or anyother similar means for the intake or discharge channels of theinventive rotating-piston compressor.

The compressor is self-cooled by way of the cooling or heat-exchangefins provided on the cylinder 21 and preferably also on the compressorbody 18 (see FIGS. 1 and 2b). It is of course also possible to cool theinventive compressor by way of forced air from a fan. If required, watercooling can be provided by means of conventional water jackets attachedto the body 18 and/or to the cylinder body 21.

For purposes of illustration, driving shaft 1 can be assumed to berotated in the clockwise sense. However, it will be understood by thoseskilled in the art, that the shaft 1, and thus the compressor, may berotated in the reverse, counter-clockwise sense. Then channels 70, 72

will maintain constant suction while channels 69, 71 provide constantdischarge. The minor structural modifications of the respective inletand outlet pipes 43 and 57, as well as 25 will be self-explanatory foroperating the compressor in this alternative mode.

It is also possible to maintain single-channel suction or discharge, orboth, by separately interconnecting the tWo intake and/or dischargechannels 69, 71, and 70, 72, respectively, by suitable conduits or othermeans.

It will be understood that no specific means have been described andillustrated for performing the various adjustments which have beendescribed earlier, like the variation of the dimensions of the pistonmembers; the changing of the specific angle between the various shafts;the administering of compressed air into the intake pipes; the changingof the volumes between the piston members; the variation in the phaseangle or difie-rence between the universal-joint systems of the twoshafts, etc. These will no doubt be self-explanatory expedients to thoseskilled in the art.

The foregoing disclosure relates only to a preferred, exemplaryembodiment of the invention compressor, which is intended to include allchanges and modifications of the example described, within the scope ofthe invention as set forth in the preceding objects and/or the appendedclaims.

What I claim is:

1. A rotating-piston compressor for air and gases, comprising a drivingshaft rotated by an extraneous prime mover at a substantially uniformspeed; two driven shafts, one of them being hollow and coaxiallysurrounding the other; two universal-joint systems operativelyinterconnected between said driving shaft and said driven shafts, forsimultaneously rotating said driven shafts with a phase difference andwith periodically recurring independent speeding-up and slowing-downphases in the velocities of each driven shaft; a casing body including aclosed cylinder body, a cylinder liner fitted into said cylinder bodyand defining a compression chamber; a pair of diametrally disposedpiston members operatively connected with each driven shaft, the twopairs being normally perpendicular With each other, and rotatable withinsaid compression chamber with a predetermined phase advance and phaselag in each pair of piston members, upon rotation of said driven shafts;a pair of diametrally disposed inlet channels through said cylinder bodyand said liner, and a pair of outlet channels spaced apart from saidinlet channels along the common axis of said driven shafts, the spacesbetween successive piston members, connected with different drivenshafts, periodically expanding and contracting so as to provide suctionfor air and gases through said inlet channels, and consecutively toprovide compression for the air and gases to deliver the same throughsaid outlet channels; said liner having cut-outs aligned with said inletand said outlet channels and substantially corresponding in theirlengths to the outer sides of said piston members, said cut-outs beinglonger than the diameters of said inlet and said outlet channels;whereby four distinct operational phases result during each halfrevoluiton of said driving shaft, three of said phases being ofsubstantially identical length and including a suction phase for the airand gases, a suction phase with compression and a compression phase,followed by the much shorter fourth phase which is a compression phasewith suction of the air and gases.

2. The compressor as defined in claim 1, wherein said phase differenceis substantially 90 between the movements of said driven shafts.

3. The compressor as defined in claim 2, wherein said universal-jointsystems each include ring members to which said driving and said drivenshafts are operatively linked by yokes, one of said yokes in each systembeing perpendicular with respect to the connected shaft while the otheryoke defines angles of 40 and 140 degrees with respect to the otherconnected shaft; the universal-joint system of one driven shaft beinglarger than the other so as to accommodate the latter within its ringmembers, With full freedom of rotation.

4. The compressor as defined in claim 3, wherein said yokes in at leastone of said universal-joint systems ar disposed for pivotal connectionwith said ring members at diametrally opposite points on the side ofsaid driving shaft, and at similar diametrally opposite points at rightangles to the afore-mentioned points on the side of said driven shaft.

5. The compressor'as defined in claim 1, wherein at least said outletchannels are interconnected for common delivery of the air and gases,and wherein at least one of said inlet channels is provided withadjustable inlet means for a lubricant.

6. The compressor as defined in claim 1, further comprising at least oneset of piston rings disposed on said piston members connected with atleast one of said driven shafts, and spring means lodged in bores, ofthe aforementioned piston members for biasing said piston rings towardsaid cylinder liner.

7. The compressor as defined in claim 1, further comprising couplingadapters between at least a pair of said inlet and said outlet channelsand corresponding portions of said cylinder body.

8. The compressor as defined in claim 7, further comprising cooling finsover at least a portion of said casing body.

9. The compressor as defined in claim 1, further comprising bearingmeans in said casing body for said hollow shaft, bearing needles betweensaid driven shafts and accommodated in recesses of the surrounded drivenshaft, and at least one oil seal associated with said driven shafts forpreventing leakage of lubricant from said casing body.

10. The compressor as defined in claim 1, wherein operation is dependentupon at least one of the parameters of the phase difference between saiduniversal-joint systems, said phase advance and said phase lag, theratios between said opertaional phases, the specific angle between theaxis of said driving shaft and the common axis of said driven shafts,the siZe of said spaces between successive piston members, the volume ofsaid compression chamber, the output capacity and the ejection pressure,and further comprising means for varying at least one of theaforementioned parameters.

References Cited UNITED STATES PATENTS 1,502,756 7/1924 Thompson 1031292,072,482 3/1937 Myard l03129 2,148,282 2/1939 Stevens 103-129 2,149,1432/1939 Landenberger 103129 2,182,269 12/ 1939 WhritenOur 123-112,503,894 4/ 1950 Wildhaber 103129 2,553,954 5/1951 Bancroft 2301442,642,807 6/1953 Linderman 12311 2,673,027 3/1954 Lipkau 23 01442,811,927 11/1957 Jansen 103129 3,061,180 10/1962 Durgin 230-1443,139,871 7/1964 Larpent 123l1 FOREIGN PATENTS 976,094 10/ 1950 France.465,211 5/1937 Great Britain.

DONLEY J. STOCKING, Primary Examiner.

W. I. GOODLIN, Assistant Examiner.

1. A ROTATING-PISTON COMPRESSOR FOR AIR AND GASES, COMPRISING A DRIVINGSHAFT ROTATED BY AN EXTRANEOUS PRIME MOVER AT A SUBSTANTIALLY UNIFORMSPEED; TWO DRIVEN SHAFTS, ONE OF THEM BEING HOLLOW AND COAXIALLYSURROUNDING THE OTHER; TWO UNIVERSAL-JOINT SYSTEMS OPERATIVELYINTERCONNECTED BETWEEN SAID DRIVING SHAFT AND SAID DRIVEN SHAFTS, FORSIMULTANEOUSLY ROTATING SAID DRIVEN SHAFTS WITH A PHASE DIFFERENCE ANDWITH PERIODICALLY RECURRING INDEPENDENT SPEEDING-UP AND SLOWING-DOWNPHASES IN THE VELOCITIES OF EACH DRIVEN SHAFT; A CASING BODY INCLUDING ACLOSED CYLINDER BODY, A CYLINDER LINER FITTED INTO SAID CYLINDER BODYAND DEFINING A COMPRESSION CHAMBER; A PAIR OF DIAMETRALLY DISPOSEDPISTON MEMBERS OPERATIVELY CONNECTED WITH EACH DRIVEN SHAFT, THE TWOPAIRS BEING NORMALLY PERPENDICULAR WITH EACH OTHER, AND ROTATABLE WITHINSAID COMPRESSION CHAMBER WITH A PREDETERMINED PHASE ADVANCE AND PHASELAG IN EACH PAIR OF PISTON MEMBERS, UPON ROTATION OF SAID DRIVEN SHAFTS;A PAIR OF DIAMETRALLY DISPOSED INLET CHANNELS THROUGH SAID CYLINDER BODYAND SAID LINER, AND A PAIR OF OUTLET CHANNELS SPACED APART FROM SAIDINLET CHANNELS ALONG THE COMMON AXIS OF S AID DRIVEN SHAFTS; THE SPACESBETWEEN SUCCESSIVE PISTON MEMBERS, CONNECTED WITH DIFFERENT DRIVENSHAFTS, PERIODICALLY EXPANDING AND CONTRACTING SO AS TO PROVIDE SUCTIONFOR AIR AND GASES THROUGH SAID INLET CHANNELS, AND CONSECUTIVELY TOPROVIDE COMPRESSION FOR TH AIR OF GASES TO DELIVER THE SAME THROUGH SAIDOUTLET CHANNELS; SAID LINER HAVING CUT-OUTS ALIGNED WITH SAID INLET ANDSAID OUTLET CHANNELS AND SUBSTANTIALLY CORRESPONDING IN THEIR LENGTHS TOTHE OUTER SIDES OF SAID PISTON MEMBERS, SAID CUT-OUTS BEING LONGER THANTHE DIAMETERS OF SAID INLET AND SAID OUTLET CHANNELS; WHEREBY FOURDISTINCT OPERATIONAL PHASES RESULT DURING EACH HALF REVOLUTION OF SAIDDRIVING SHAFT, THREE OF SAID PHASES BEING OF SUBSTANTIALLY IDENTICALLENGTH AND INCLUDING A SUCTION PHASE FOR THE AIR AND GASES, A SUCTIONPHASE WITH COMPRESSION AND A COMPRESSION PHASE, FOLLOWED BY THE MUCHSHORTER FOURTH PHASE WHICH IS A COMPRESSION PHASE WITH SUCTION OF THEAIR AND GASES.